This is why I never considered buying one of these...
As for physically different keyboards, I've found it to be a much lesser issue than I expected. I recently got a Moonlander [2] due to general hand and wrist pain that could only be attributed to strain from typing.
I took care to map the layout quite closely and the physical layout was almost immediately usable. I started at around 2/3 my normal typing speed but was back to 100% in a matter of a week.
Going back to a normal keyboard takes minimal effort. I can still type on them quickly, I just loathe them more than I did before now that I know how much more comfortable it could be.
It is maybe a bit annyoing if I have to type in german a lot on some days, but it is less annoying then to keep an extra layout. And since I sometimes have to type in french and often in russian... well, you get the idea, it would be a mess of 4 keyboard layouts. With special characters I can push the amount of keyboard layouts just to colemak and russian.